diff --git a/tests/bench_msg_pingpong/tests/01-run.py b/tests/bench_msg_pingpong/tests/01-run.py
index 1e6c34d6fbd6677369c1002eaee726a4d46a6843..7332378b99eb1fca1532db0ade807fffecb0bd52 100755
--- a/tests/bench_msg_pingpong/tests/01-run.py
+++ b/tests/bench_msg_pingpong/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/bench_mutex_pingpong/tests/01-run.py b/tests/bench_mutex_pingpong/tests/01-run.py
index 1e6c34d6fbd6677369c1002eaee726a4d46a6843..7332378b99eb1fca1532db0ade807fffecb0bd52 100755
--- a/tests/bench_mutex_pingpong/tests/01-run.py
+++ b/tests/bench_mutex_pingpong/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/bench_sched_nop/tests/01-run.py b/tests/bench_sched_nop/tests/01-run.py
index 1e6c34d6fbd6677369c1002eaee726a4d46a6843..7332378b99eb1fca1532db0ade807fffecb0bd52 100755
--- a/tests/bench_sched_nop/tests/01-run.py
+++ b/tests/bench_sched_nop/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/bench_thread_flags_pingpong/tests/01-run.py b/tests/bench_thread_flags_pingpong/tests/01-run.py
index 1e6c34d6fbd6677369c1002eaee726a4d46a6843..7332378b99eb1fca1532db0ade807fffecb0bd52 100755
--- a/tests/bench_thread_flags_pingpong/tests/01-run.py
+++ b/tests/bench_thread_flags_pingpong/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/bench_thread_yield_pingpong/tests/01-run.py b/tests/bench_thread_yield_pingpong/tests/01-run.py
index 1e6c34d6fbd6677369c1002eaee726a4d46a6843..7332378b99eb1fca1532db0ade807fffecb0bd52 100755
--- a/tests/bench_thread_yield_pingpong/tests/01-run.py
+++ b/tests/bench_thread_yield_pingpong/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/bitarithm_timings/tests/01-run.py b/tests/bitarithm_timings/tests/01-run.py
index 386d06136fd05f34adc45cf6b4b85a3bbf4ff14a..9e1cd77b3dffa2dfc0ef2f701ea6e3a994699377 100755
--- a/tests/bitarithm_timings/tests/01-run.py
+++ b/tests/bitarithm_timings/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/bloom_bytes/tests/01-run.py b/tests/bloom_bytes/tests/01-run.py
index 699986feba787714294a56b196f1c2f78901df01..699eb2ee21729c0f8a2e2b87c3420e3d66a335ce 100755
--- a/tests/bloom_bytes/tests/01-run.py
+++ b/tests/bloom_bytes/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/buttons/tests/01-run.py b/tests/buttons/tests/01-run.py
index 3be148a5a2d966b8bb236b2084f1362199e805e1..4697ef690f689e8ad6f6df8add385628b64265e0 100755
--- a/tests/buttons/tests/01-run.py
+++ b/tests/buttons/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/cb_mux/tests/01-run.py b/tests/cb_mux/tests/01-run.py
index 0549c9657b39c714d715f128998b153a43995b92..989ddecb8c943c5dbeb0826be206dd97a4e69266 100755
--- a/tests/cb_mux/tests/01-run.py
+++ b/tests/cb_mux/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/cb_mux_bench/tests/01-run.py b/tests/cb_mux_bench/tests/01-run.py
index af84928ca2e264d5f8b651621ac638fe55c84f0c..b0e0518bf77b8d796a22d597b489c350eed00a0b 100755
--- a/tests/cb_mux_bench/tests/01-run.py
+++ b/tests/cb_mux_bench/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/cbor/tests/01-run.py b/tests/cbor/tests/01-run.py
index b420a17e79edf4aefa0054c0335361d3a048fa6b..fdef422e3b1fae9e17608169c64be18467d9e24f 100755
--- a/tests/cbor/tests/01-run.py
+++ b/tests/cbor/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 ACCEPTED_ERROR = 20
diff --git a/tests/cpp11_condition_variable/tests/01-run.py b/tests/cpp11_condition_variable/tests/01-run.py
index 158d6e36c623bd547859725c2c9eb46c81d74a3f..90f5ebec68624248c00af97ffe947843bedb013b 100755
--- a/tests/cpp11_condition_variable/tests/01-run.py
+++ b/tests/cpp11_condition_variable/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/cpp11_mutex/tests/01-run.py b/tests/cpp11_mutex/tests/01-run.py
index 3b768c8a22cba1c5a2ad8b02f4597e6d36832584..65990091c7b4076a1cf7c7e29c04b465273e0f4e 100755
--- a/tests/cpp11_mutex/tests/01-run.py
+++ b/tests/cpp11_mutex/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/cpp11_thread/tests/01-run.py b/tests/cpp11_thread/tests/01-run.py
index c67b01a44df540d762afd4d3f325605c41ca59ca..f6d92f5571de2dbf3ae378186b99f9d3bb86de2c 100755
--- a/tests/cpp11_thread/tests/01-run.py
+++ b/tests/cpp11_thread/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/driver_ds1307/tests/01-run.py b/tests/driver_ds1307/tests/01-run.py
index 992fa0fca904245037511f2de4d68a3922152764..d234526e0bcd926befa6ba1df8ce5705d841ba0b 100755
--- a/tests/driver_ds1307/tests/01-run.py
+++ b/tests/driver_ds1307/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/driver_grove_ledbar/tests/01-run.py b/tests/driver_grove_ledbar/tests/01-run.py
index e2be76436be51e9d7f804419e0a8a77d082d8fc5..8141bffd57e81dbfd6660056bfea88c89dc4d436 100755
--- a/tests/driver_grove_ledbar/tests/01-run.py
+++ b/tests/driver_grove_ledbar/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/driver_hd44780/tests/01-run.py b/tests/driver_hd44780/tests/01-run.py
index 87b126d4692f45a2e54f5d01c376168de7c2a8ee..29c6ba53efd2f0a0b8578baf39b6e743a0acfb03 100755
--- a/tests/driver_hd44780/tests/01-run.py
+++ b/tests/driver_hd44780/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/driver_my9221/tests/01-run.py b/tests/driver_my9221/tests/01-run.py
index 39a482cfe551c6de8330cfa716acf50aa3a24fd6..7592b61fbc267fb6faa2936f719db39993daaf2c 100755
--- a/tests/driver_my9221/tests/01-run.py
+++ b/tests/driver_my9221/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/events/tests/01-run.py b/tests/events/tests/01-run.py
index d1d17996b98dc44a272f58072d6257bad0f60f29..b97b0a1d1dc4483b37e772f60195e1799fff99d6 100755
--- a/tests/events/tests/01-run.py
+++ b/tests/events/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/evtimer_msg/tests/01-run.py b/tests/evtimer_msg/tests/01-run.py
index 3e01c876a7ac7df1085afcb0523c88cc0af4ae84..ce2736c1b63667f3d2975603d485111a6f2940a8 100755
--- a/tests/evtimer_msg/tests/01-run.py
+++ b/tests/evtimer_msg/tests/01-run.py
@@ -7,7 +7,6 @@
 # directory for more details.
 
 from __future__ import print_function
-import os
 import sys
 
 ACCEPTED_ERROR = 20
diff --git a/tests/evtimer_underflow/tests/01-run.py b/tests/evtimer_underflow/tests/01-run.py
index 7f3ccd72eaea4c3dab1447c5d1270a69179215f9..04e79d32b93feb2da7ad9b04e01449f086ecea19 100755
--- a/tests/evtimer_underflow/tests/01-run.py
+++ b/tests/evtimer_underflow/tests/01-run.py
@@ -7,7 +7,6 @@
 # directory for more details.
 
 from __future__ import print_function
-import os
 import sys
 
 how_many = 100
diff --git a/tests/float/tests/01-run.py b/tests/float/tests/01-run.py
index fa0eb5d05356c2bf03e2a0826ea962182c8219c9..ffbfae9bc0064e31bff6421f9966956a1758b0db 100755
--- a/tests/float/tests/01-run.py
+++ b/tests/float/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 # It takes 35 seconds on wsn430, so add some margin
diff --git a/tests/fmt_print/tests/01-run.py b/tests/fmt_print/tests/01-run.py
index 558903a8f7fd788a91da187a079b2321e3f08275..12209df798f7e000a67f0fabee80a120e3cff7a7 100755
--- a/tests/fmt_print/tests/01-run.py
+++ b/tests/fmt_print/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_ipv6_ext/tests/01-run.py b/tests/gnrc_ipv6_ext/tests/01-run.py
index dec27a34ef19ea198eea60110a5da6b1158a66b1..b0277af8ee23deeceb7c60cabb499d55427c6b35 100755
--- a/tests/gnrc_ipv6_ext/tests/01-run.py
+++ b/tests/gnrc_ipv6_ext/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_ipv6_nib/tests/01-run.py b/tests/gnrc_ipv6_nib/tests/01-run.py
index 402645aa86eba1ade133a5aba3e2b8b8fae39b2e..7df19bc0bfd64810652fec246288745da2ca8da5 100755
--- a/tests/gnrc_ipv6_nib/tests/01-run.py
+++ b/tests/gnrc_ipv6_nib/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_ipv6_nib_6ln/tests/01-run.py b/tests/gnrc_ipv6_nib_6ln/tests/01-run.py
index 402645aa86eba1ade133a5aba3e2b8b8fae39b2e..7df19bc0bfd64810652fec246288745da2ca8da5 100755
--- a/tests/gnrc_ipv6_nib_6ln/tests/01-run.py
+++ b/tests/gnrc_ipv6_nib_6ln/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_ndp/tests/01-run.py b/tests/gnrc_ndp/tests/01-run.py
index 7b5d5164ffbf3d414223afb295b03dadcd2f722e..c36c003427aa0c79cb07bdd108c71bf3d1226015 100755
--- a/tests/gnrc_ndp/tests/01-run.py
+++ b/tests/gnrc_ndp/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_netif/tests/01-run.py b/tests/gnrc_netif/tests/01-run.py
index 2678e55bfc032003a818b917da1b8b74ec0c6ed9..7c722a6ffbe096907777a8ff4cd6289e6d31c0be 100755
--- a/tests/gnrc_netif/tests/01-run.py
+++ b/tests/gnrc_netif/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_sixlowpan/tests/01-run.py b/tests/gnrc_sixlowpan/tests/01-run.py
index 97df29c9584f6dd704881dee0edbd2b7e4c0c999..2254e0e2efcc519b22dabbcfa510c06bcb603676 100755
--- a/tests/gnrc_sixlowpan/tests/01-run.py
+++ b/tests/gnrc_sixlowpan/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_sock_ip/tests/01-run.py b/tests/gnrc_sock_ip/tests/01-run.py
index 5e730dc9a88eb84a8ec632ec8a1b4a838a209be6..7daf6b0f27b4e7d85f93e98004b2f79188cf859c 100755
--- a/tests/gnrc_sock_ip/tests/01-run.py
+++ b/tests/gnrc_sock_ip/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/gnrc_sock_udp/tests/01-run.py b/tests/gnrc_sock_udp/tests/01-run.py
index 19cf6585d7c8a04509a15458b3db43ce76053171..890ee64664032aa515d39adb8e76b92387bebfe8 100755
--- a/tests/gnrc_sock_udp/tests/01-run.py
+++ b/tests/gnrc_sock_udp/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/irq/tests/01-run.py b/tests/irq/tests/01-run.py
index e6a7407644d1cc96d493bb0eacb0665aa610b65b..164d335653b92339ae6e47fc4b388cad01c9ef7a 100755
--- a/tests/irq/tests/01-run.py
+++ b/tests/irq/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/isr_yield_higher/tests/test.py b/tests/isr_yield_higher/tests/test.py
index 5ff95c57a520d1feb455aba34d9dd26b939f385f..7df1e1b5c46401f4ce36fbaa5b9b06aeca4f1740 100755
--- a/tests/isr_yield_higher/tests/test.py
+++ b/tests/isr_yield_higher/tests/test.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/libc_newlib/tests/01-run.py b/tests/libc_newlib/tests/01-run.py
index f5a55fd74ed494a6c7d1b22f93b3a668e240f959..3cb9911b3b14711922dc726c7c582ba7cad029b4 100755
--- a/tests/libc_newlib/tests/01-run.py
+++ b/tests/libc_newlib/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/libfixmath/tests/01-run.py b/tests/libfixmath/tests/01-run.py
index fe0e569f83d3c52fb94d28d96acc835b6364a57c..147d68672dbae434687b6857479c62eb2a34bc57 100755
--- a/tests/libfixmath/tests/01-run.py
+++ b/tests/libfixmath/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/libfixmath_unittests/tests/01-run.py b/tests/libfixmath_unittests/tests/01-run.py
index c26be21b75ddc3d1ead63293bf71eb11bbd78c6a..43c877c5a1cb2b394a89d3d6e1a0441091fad43e 100755
--- a/tests/libfixmath_unittests/tests/01-run.py
+++ b/tests/libfixmath_unittests/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 # Float and print operations are slow on boards
diff --git a/tests/lwip_sock_ip/tests/01-run.py b/tests/lwip_sock_ip/tests/01-run.py
index efe2b398d98121a1163a30c23a17f6a66935bc63..973c5db84295a7bd74cf43086ec1e30caa032bcb 100755
--- a/tests/lwip_sock_ip/tests/01-run.py
+++ b/tests/lwip_sock_ip/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/lwip_sock_tcp/tests/01-run.py b/tests/lwip_sock_tcp/tests/01-run.py
index 2d9fae84db36e09a5dde0ff2f8c0de7d4282e09c..1e3cba2f140bf1ba7595e0047e9ab23ffbd6906d 100755
--- a/tests/lwip_sock_tcp/tests/01-run.py
+++ b/tests/lwip_sock_tcp/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/lwip_sock_udp/tests/01-run.py b/tests/lwip_sock_udp/tests/01-run.py
index 5acc81904f56d5bafee05bf702023d8d87eb05d8..eb81e986c5d820723a6d3bf1f8ac9cad00d1c68d 100755
--- a/tests/lwip_sock_udp/tests/01-run.py
+++ b/tests/lwip_sock_udp/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/msg_avail/tests/01-run.py b/tests/msg_avail/tests/01-run.py
index d1d17996b98dc44a272f58072d6257bad0f60f29..b97b0a1d1dc4483b37e772f60195e1799fff99d6 100755
--- a/tests/msg_avail/tests/01-run.py
+++ b/tests/msg_avail/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/msg_send_receive/tests/01-run.py b/tests/msg_send_receive/tests/01-run.py
index 9fc6cd5864e255eed817b26ebec68296e40bfb33..30ba904615ac0475336a8493767d1047e1b91b8b 100755
--- a/tests/msg_send_receive/tests/01-run.py
+++ b/tests/msg_send_receive/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/msg_try_receive/tests/01-run.py b/tests/msg_try_receive/tests/01-run.py
index 30fb32ca22e408b0bb277ce2ea1e7fb197abbc37..3c736de0e2e883fd10c3c95bd60dbcae291ae5d2 100755
--- a/tests/msg_try_receive/tests/01-run.py
+++ b/tests/msg_try_receive/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/mutex_order/tests/01-run.py b/tests/mutex_order/tests/01-run.py
index 424c9e7a337854e636dbe50e4c025654757b89f2..d0f278857e880de5a54a5bc382759f989f0af58b 100755
--- a/tests/mutex_order/tests/01-run.py
+++ b/tests/mutex_order/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 thread_prio = {
diff --git a/tests/mutex_unlock_and_sleep/tests/01-run.py b/tests/mutex_unlock_and_sleep/tests/01-run.py
index 0505ac2c9249bf76c7bb7e38e71c1aa35e3c47b4..b968bc9c9f7c373312d35144f37dba8c9c4116c5 100755
--- a/tests/mutex_unlock_and_sleep/tests/01-run.py
+++ b/tests/mutex_unlock_and_sleep/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/netdev_test/tests/01-run.py b/tests/netdev_test/tests/01-run.py
index 62ce660e1cbbc25970fc08936c9ddecf79974b19..c4d0b2f33861ac5d396c7f38eac11f5f2bbfcc2a 100755
--- a/tests/netdev_test/tests/01-run.py
+++ b/tests/netdev_test/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/netstats_l2/tests/01-run.py b/tests/netstats_l2/tests/01-run.py
index c0d84e2342aa993698b738a823574d8c321d8931..04962da71042e36a4b728ebbfdca25ca28be4b11 100755
--- a/tests/netstats_l2/tests/01-run.py
+++ b/tests/netstats_l2/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/nhdp/tests/01-run.py b/tests/nhdp/tests/01-run.py
index a0ed853f53635e6941a63f0adfc482d895b121a1..968f07cdbbcddc65976791e93e389c38d02124c3 100755
--- a/tests/nhdp/tests/01-run.py
+++ b/tests/nhdp/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/od/tests/01-run.py b/tests/od/tests/01-run.py
index c552865f5d658caef6e551a2127f6cc4dcd08098..31cf2ae1de66ce4b12c0514a65b3c09e59097154 100755
--- a/tests/od/tests/01-run.py
+++ b/tests/od/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/od/tests/02-run.py b/tests/od/tests/02-run.py
index c28df9ec3797b6d288dcdb3219ff4f1efc5929a9..e998fa6c2ca18d556a156a97ddff5710e805fabc 100755
--- a/tests/od/tests/02-run.py
+++ b/tests/od/tests/02-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/periph_gpio/tests/02-bench.py b/tests/periph_gpio/tests/02-bench.py
index 09ed4e401bf4cbe447f9548ef98098f24f5cf5d5..016fc529feeeeddd8c530826570f383c085f9df6 100755
--- a/tests/periph_gpio/tests/02-bench.py
+++ b/tests/periph_gpio/tests/02-bench.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/periph_timer/tests/01-run.py b/tests/periph_timer/tests/01-run.py
index 6648eb4ff7e510a5202877e9d2146ca959230097..dc11d2bb214f31f599dc0ebd502d68aa119efcd7 100755
--- a/tests/periph_timer/tests/01-run.py
+++ b/tests/periph_timer/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/pipe/tests/01-run.py b/tests/pipe/tests/01-run.py
index 9623d436e5e6662fbfb3151949f84fe8f5a0d68c..3bec382418dbca0102843e07922afc1250d6b340 100755
--- a/tests/pipe/tests/01-run.py
+++ b/tests/pipe/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pkg_cayenne-lpp/tests/01-run.py b/tests/pkg_cayenne-lpp/tests/01-run.py
index 4b99eedb8ce00d3b9b52d01d5c9c3b4b73169f8a..593b9e625b5083c6f916e23ba1d69eb7520ed6fd 100755
--- a/tests/pkg_cayenne-lpp/tests/01-run.py
+++ b/tests/pkg_cayenne-lpp/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 NB_TESTS = 3
diff --git a/tests/pkg_fatfs_vfs/tests/01-run.py b/tests/pkg_fatfs_vfs/tests/01-run.py
index d1e4987cf8035b558aea88991f332c53b29e8fff..7cfe0457f80d2d0d4eee45366fb529857b8df94d 100755
--- a/tests/pkg_fatfs_vfs/tests/01-run.py
+++ b/tests/pkg_fatfs_vfs/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/pkg_jsmn/tests/01-run.py b/tests/pkg_jsmn/tests/01-run.py
index 9a0bf6b0138bec039c0c2434ade5a954d03bc555..950b33af29268df1fc69aa3a3c49c3bccb64798c 100755
--- a/tests/pkg_jsmn/tests/01-run.py
+++ b/tests/pkg_jsmn/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pkg_libcoap/tests/01-run.py b/tests/pkg_libcoap/tests/01-run.py
index 657ff0736532115288defba5aa953815e66d56c5..a61abfffae3559f3fb5eb5479057285b394d2e87 100755
--- a/tests/pkg_libcoap/tests/01-run.py
+++ b/tests/pkg_libcoap/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py b/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py
index 7167faa9c71b28586c6a932fe0729b4290f79043..26ff33cb14b5fc44055b21729f01051bee7a6463 100755
--- a/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py
+++ b/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pkg_micro-ecc/tests/01-run.py b/tests/pkg_micro-ecc/tests/01-run.py
index 88ffb443acade77c7121fd893e1408d90bf6b8e4..e4d6ef2c0bfc5da274a8f37408848055e276126b 100755
--- a/tests/pkg_micro-ecc/tests/01-run.py
+++ b/tests/pkg_micro-ecc/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pkg_minmea/tests/01-run.py b/tests/pkg_minmea/tests/01-run.py
index af4b043ffd1b24544bbaf1d4b70b8ad2e5d09f80..1600bbf7bd8c19e0db5920eb7ec667de97080371 100755
--- a/tests/pkg_minmea/tests/01-run.py
+++ b/tests/pkg_minmea/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pkg_monocypher/tests/01-run.py b/tests/pkg_monocypher/tests/01-run.py
index 7e0ce7ad4cf522e59f05d93d00e8cfd7f5b4942a..b750a448e4f84ac2f8b1d39858ba311b6502d01c 100755
--- a/tests/pkg_monocypher/tests/01-run.py
+++ b/tests/pkg_monocypher/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/pkg_tiny-asn1/tests/01-run.py b/tests/pkg_tiny-asn1/tests/01-run.py
index 06d979766aef4dc6878d91711c4eb07e5308d3c9..b582e3a664b47706c447967c70407b433fe25187 100755
--- a/tests/pkg_tiny-asn1/tests/01-run.py
+++ b/tests/pkg_tiny-asn1/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/pkg_tinycbor/tests/01-run.py b/tests/pkg_tinycbor/tests/01-run.py
index 7b39d74443811c52fd1ec0ada1573b763bef8bce..525d41b06ca3672c9393b7cd5a84f151bcfa3608 100755
--- a/tests/pkg_tinycbor/tests/01-run.py
+++ b/tests/pkg_tinycbor/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/pkg_tinycrypt/tests/01-run.py b/tests/pkg_tinycrypt/tests/01-run.py
index 4e1df03e2d82e273b362906599bc453ff7bee2e2..479d3d58cea22e861c12553cd981e47d993e1294 100755
--- a/tests/pkg_tinycrypt/tests/01-run.py
+++ b/tests/pkg_tinycrypt/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/pkg_u8g2/tests/01-run.py b/tests/pkg_u8g2/tests/01-run.py
index 796072098dd788c71ce92a77715a72246567a310..a9f4333a419291a2f532f4c976cb7dde0357e4eb 100755
--- a/tests/pkg_u8g2/tests/01-run.py
+++ b/tests/pkg_u8g2/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 EXPECTED_STDOUT = (
diff --git a/tests/pkg_ucglib/tests/01-run.py b/tests/pkg_ucglib/tests/01-run.py
index 2d7aa38066b111eff2b8cf665107871a4c93d2fd..92bf6797643c44daca282e1a26ea2c3a90f8b8a6 100755
--- a/tests/pkg_ucglib/tests/01-run.py
+++ b/tests/pkg_ucglib/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 EXPECTED_STDOUT = (
diff --git a/tests/pkg_umorse/tests/01-run.py b/tests/pkg_umorse/tests/01-run.py
index 550cda48d6baf3194f362c661bb5d5770641a761..cb8267ea59379647593f1d52f83c6d27b85a3fef 100755
--- a/tests/pkg_umorse/tests/01-run.py
+++ b/tests/pkg_umorse/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/posix_semaphore/tests/01-run.py b/tests/posix_semaphore/tests/01-run.py
index 05d1154cc30f4642598f8ef5ee5dfa8967578eff..f702f67d130e539ab88d6afbef78c38b95329c42 100755
--- a/tests/posix_semaphore/tests/01-run.py
+++ b/tests/posix_semaphore/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/posix_time/tests/01-run.py b/tests/posix_time/tests/01-run.py
index 4d38bed1d974becef9eb7218e4c129243d39a712..86095f3d20d9230a6f8198aee8a47e8f9f5a0cec 100755
--- a/tests/posix_time/tests/01-run.py
+++ b/tests/posix_time/tests/01-run.py
@@ -8,7 +8,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 import time
 
diff --git a/tests/ps_schedstatistics/tests/01-run.py b/tests/ps_schedstatistics/tests/01-run.py
index 751117e39aaf8eec7ee185a9d91f96aa0b191f34..3292007bebeb033db39703a47987b31e99a9a738 100755
--- a/tests/ps_schedstatistics/tests/01-run.py
+++ b/tests/ps_schedstatistics/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 PS_EXPECTED = (
diff --git a/tests/pthread/tests/01-run.py b/tests/pthread/tests/01-run.py
index cf846ad84e4fd95220767b97f0da0673cd5eb4f0..0b7896edf5a542bccc797b4dd586bd459a08805b 100755
--- a/tests/pthread/tests/01-run.py
+++ b/tests/pthread/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 import math
 
diff --git a/tests/pthread_barrier/tests/01-run.py b/tests/pthread_barrier/tests/01-run.py
index ef724c76bfa4d523a8b7ed2ce8ff1f841cc2fb22..7a7f4a9d288be24f6148b14299cd75edf9f0bfa1 100755
--- a/tests/pthread_barrier/tests/01-run.py
+++ b/tests/pthread_barrier/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pthread_cleanup/tests/01-run.py b/tests/pthread_cleanup/tests/01-run.py
index 31380dbf980af0143481f2063d0dda90d1965281..e8ccbd32f751b43c5f222afbcac9857c426c504a 100755
--- a/tests/pthread_cleanup/tests/01-run.py
+++ b/tests/pthread_cleanup/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pthread_condition_variable/tests/01-run.py b/tests/pthread_condition_variable/tests/01-run.py
index efbc17d83097ed06e13b2cf0f7afa4ba4ad47d04..1b290d33f414d4fe6b2570d3e4d3edf155aebeff 100755
--- a/tests/pthread_condition_variable/tests/01-run.py
+++ b/tests/pthread_condition_variable/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pthread_cooperation/tests/01-run.py b/tests/pthread_cooperation/tests/01-run.py
index 56ee6e0eeebd6df12ed46ff717f9fb389991d4a7..6d2886205181df3e85a37f658bb6720ec8660530 100755
--- a/tests/pthread_cooperation/tests/01-run.py
+++ b/tests/pthread_cooperation/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pthread_rwlock/tests/01-run.py b/tests/pthread_rwlock/tests/01-run.py
index 414c8b52c676d90b04360fdb778aa5ce2fad63ef..f49fed0b95a7674888b288bc222cef004879e882 100755
--- a/tests/pthread_rwlock/tests/01-run.py
+++ b/tests/pthread_rwlock/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/pthread_tls/tests/01-run.py b/tests/pthread_tls/tests/01-run.py
index b21fb146665ce9bf79329d2f792be1a1206e297d..ce97c472fecb492731a4afadff7d7786e9f1da37 100755
--- a/tests/pthread_tls/tests/01-run.py
+++ b/tests/pthread_tls/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/rmutex/tests/01-run.py b/tests/rmutex/tests/01-run.py
index 17cacc1129c459c500b6d088119b98fdd37c36cc..db8e72307fe57c4403cca7c033cde147b8ddcd06 100755
--- a/tests/rmutex/tests/01-run.py
+++ b/tests/rmutex/tests/01-run.py
@@ -8,7 +8,6 @@
 
 # Author: Martin Elshuber <martin.elshuber@theobroma-systems.com>
 
-import os
 import sys
 
 thread_prio = {
diff --git a/tests/rng/tests/01-run.py b/tests/rng/tests/01-run.py
index fc41328cbe0475b76be6a16ce1057423c6036e8a..3be36d82127308c30d96b469fab4a6f045814d9d 100755
--- a/tests/rng/tests/01-run.py
+++ b/tests/rng/tests/01-run.py
@@ -7,7 +7,6 @@
 # directory for more details.
 
 import sys
-import os
 import re
 
 
diff --git a/tests/sched_testing/tests/01-run.py b/tests/sched_testing/tests/01-run.py
index 8bb0239ccbf625483fee311c2d7b92b0b048ceea..e5ea3eefde8a9d449109e59132f807c5e4f45f15 100755
--- a/tests/sched_testing/tests/01-run.py
+++ b/tests/sched_testing/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/shell/tests/01-run.py b/tests/shell/tests/01-run.py
index cd5fabcd933909c0d70bdc3c9f63bd645d167c49..8dc399a49cd5e144d18da6437029029fc2bdca2d 100755
--- a/tests/shell/tests/01-run.py
+++ b/tests/shell/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 EXPECTED_HELP = (
diff --git a/tests/sizeof_tcb/tests/01-run.py b/tests/sizeof_tcb/tests/01-run.py
index 6c754b72d7828102e184ba4ae53798e1d062fd12..31564969218622232c23064e91c21f3a4452d15d 100755
--- a/tests/sizeof_tcb/tests/01-run.py
+++ b/tests/sizeof_tcb/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/ssp/tests/01-run.py b/tests/ssp/tests/01-run.py
index 868eb03418cd6c6b7cf10c98aafd611036b44e5e..2def877d0ef0bf0e1630601d4f7a835808be621f 100755
--- a/tests/ssp/tests/01-run.py
+++ b/tests/ssp/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/struct_tm_utility/tests/01-run.py b/tests/struct_tm_utility/tests/01-run.py
index 8bd04d94ac76826d6a3b7a5c60e84643066a3740..b9fb8939b14cda94cf8c5c8f7cc796a3da230f40 100755
--- a/tests/struct_tm_utility/tests/01-run.py
+++ b/tests/struct_tm_utility/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 import calendar
 import datetime
diff --git a/tests/thread_basic/tests/01-run.py b/tests/thread_basic/tests/01-run.py
index 2864a30f46683bebe42cfeefdb85d848cca3dea9..32bb41585d4118ace678caef8d631561fbd20b5e 100755
--- a/tests/thread_basic/tests/01-run.py
+++ b/tests/thread_basic/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/thread_cooperation/tests/01-run.py b/tests/thread_cooperation/tests/01-run.py
index a7728af7d9941915c0bce08c4a55a551c270d052..24cabc46aba814129cfa1b3fca152885a663498e 100755
--- a/tests/thread_cooperation/tests/01-run.py
+++ b/tests/thread_cooperation/tests/01-run.py
@@ -7,7 +7,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/thread_exit/tests/01-run.py b/tests/thread_exit/tests/01-run.py
index 432b4c99e0131c6e414aa150906951de7a68db45..6a7f96c9f8f394ca2940e85cfcd337bf84f9c744 100755
--- a/tests/thread_exit/tests/01-run.py
+++ b/tests/thread_exit/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/thread_flags/tests/01-run.py b/tests/thread_flags/tests/01-run.py
index 38c978b5c277587fc07d2168c0495238bde080ab..e6551692ea37ed7bc3e8bd807d8703de3da9404b 100755
--- a/tests/thread_flags/tests/01-run.py
+++ b/tests/thread_flags/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/thread_flags_xtimer/tests/01-run.py b/tests/thread_flags_xtimer/tests/01-run.py
index 004984efd779fdd2e2b7d9cfe4a6b7d36eb76aa9..27d7e19e200030d4afb6e78c12e27391d964b0aa 100755
--- a/tests/thread_flags_xtimer/tests/01-run.py
+++ b/tests/thread_flags_xtimer/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/thread_flood/tests/01-run.py b/tests/thread_flood/tests/01-run.py
index 97c0dd1435cf94daf8698d5905dfed73da80f17b..47615f813e66fa3facc0c1345e6bed3a66711d6c 100755
--- a/tests/thread_flood/tests/01-run.py
+++ b/tests/thread_flood/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/thread_msg/tests/01-run.py b/tests/thread_msg/tests/01-run.py
index be06a8afca35f8c54e10925d685ace47ccab082b..5a4ba9c34f1ec96647b8466b0e54c95d45c11f9f 100755
--- a/tests/thread_msg/tests/01-run.py
+++ b/tests/thread_msg/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/thread_msg_block_w_queue/tests/01-run.py b/tests/thread_msg_block_w_queue/tests/01-run.py
index 190c8d5cba4af591c4056b52ba3fa93ee52f9a32..4b1633215d8c97cbfc519e92bc17dff7b90a41f5 100755
--- a/tests/thread_msg_block_w_queue/tests/01-run.py
+++ b/tests/thread_msg_block_w_queue/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/thread_msg_block_wo_queue/tests/01-run.py b/tests/thread_msg_block_wo_queue/tests/01-run.py
index 190c8d5cba4af591c4056b52ba3fa93ee52f9a32..4b1633215d8c97cbfc519e92bc17dff7b90a41f5 100755
--- a/tests/thread_msg_block_wo_queue/tests/01-run.py
+++ b/tests/thread_msg_block_wo_queue/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/thread_msg_seq/tests/01-run.py b/tests/thread_msg_seq/tests/01-run.py
index f479800f60e8fbc02b1df1c2a99be14a312bc5e5..a7e6bf016ec856a2f35ec26f9382222c55afb323 100755
--- a/tests/thread_msg_seq/tests/01-run.py
+++ b/tests/thread_msg_seq/tests/01-run.py
@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import os
 import sys
 
 
diff --git a/tests/thread_race/tests/01-run.py b/tests/thread_race/tests/01-run.py
index 97680488912cfcb02e9ee3db13ea55746d28f935..4578367e59d54697944bf8f402485873a2a49336 100755
--- a/tests/thread_race/tests/01-run.py
+++ b/tests/thread_race/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/trace/tests/01-run.py b/tests/trace/tests/01-run.py
index 158a583a2b22d948383120ba875378065c72e837..6dc519a47ee929a34245738e1ac2631fe49dc91b 100755
--- a/tests/trace/tests/01-run.py
+++ b/tests/trace/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/trickle/tests/01-run.py b/tests/trickle/tests/01-run.py
index 963f7c04a4e961ded0e78a6c149e02642f1ca465..24960cf9374b9ebbe032e6b123831252b3bbf5d8 100755
--- a/tests/trickle/tests/01-run.py
+++ b/tests/trickle/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/unittests/tests/01-run.py b/tests/unittests/tests/01-run.py
index 56f8975f8ee047594fc07e344acf94b7e5b09255..76920e39d85763a0803ea6a16420127f4f817533 100755
--- a/tests/unittests/tests/01-run.py
+++ b/tests/unittests/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_hang/tests/01-run.py b/tests/xtimer_hang/tests/01-run.py
index 765ebf5ba49c675f854785d4695bef9f7b2a099c..fe24604164d1da5ebad322ac35c5e6e0eaa148a7 100755
--- a/tests/xtimer_hang/tests/01-run.py
+++ b/tests/xtimer_hang/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_msg/tests/01-run.py b/tests/xtimer_msg/tests/01-run.py
index 9426896d22d03f269f055b6e1701db9fd07e130d..3b185d7b32999b25646d932a07cb8b0fe8c4f993 100755
--- a/tests/xtimer_msg/tests/01-run.py
+++ b/tests/xtimer_msg/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_msg_receive_timeout/tests/01-run.py b/tests/xtimer_msg_receive_timeout/tests/01-run.py
index 96f7bb5268c7a5236e63203abd10829be2a42b00..6d60d859abedd7ab130d39a49ab7538310a14a56 100755
--- a/tests/xtimer_msg_receive_timeout/tests/01-run.py
+++ b/tests/xtimer_msg_receive_timeout/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_now64_continuity/tests/01-run.py b/tests/xtimer_now64_continuity/tests/01-run.py
index f4e9a5e08b68fbbf7fd7a28a53cfa9b63110bf8e..149f1ae426687cff9fca7922eab9beb34d9c7801 100755
--- a/tests/xtimer_now64_continuity/tests/01-run.py
+++ b/tests/xtimer_now64_continuity/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_periodic_wakeup/tests/01-run.py b/tests/xtimer_periodic_wakeup/tests/01-run.py
index e6d052b3c63a7d1ef867496e4052faaf40ac374a..911894d443e9b4bfa37c587706e22e9642ab53a2 100755
--- a/tests/xtimer_periodic_wakeup/tests/01-run.py
+++ b/tests/xtimer_periodic_wakeup/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_remove/tests/01-run.py b/tests/xtimer_remove/tests/01-run.py
index ee0fa4fd415178b903f69643bc85e49492035738..452a8830c91cb18e841d1546b1d03243e2210c90 100755
--- a/tests/xtimer_remove/tests/01-run.py
+++ b/tests/xtimer_remove/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_reset/tests/01-run.py b/tests/xtimer_reset/tests/01-run.py
index 67bb037a43252fe558cb36eff462d1b9552ebd71..1576d4c54be5e8fa10a5bc1d15f6b7e6daa70bfb 100755
--- a/tests/xtimer_reset/tests/01-run.py
+++ b/tests/xtimer_reset/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 
 
diff --git a/tests/xtimer_usleep/tests/01-run.py b/tests/xtimer_usleep/tests/01-run.py
index b72f052b1e5f387417f5b656b7e962e60bb3ab3c..f2d85f5b94e3a5677b67e2d2afd9f9ef3bd222b5 100755
--- a/tests/xtimer_usleep/tests/01-run.py
+++ b/tests/xtimer_usleep/tests/01-run.py
@@ -9,7 +9,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 import time
 
diff --git a/tests/xtimer_usleep_short/tests/01-run.py b/tests/xtimer_usleep_short/tests/01-run.py
index 86a0038eff9065e4e77ac3df80246fbb403d065e..8af1779d4e70619f1e9e18790222f39a9094a34a 100755
--- a/tests/xtimer_usleep_short/tests/01-run.py
+++ b/tests/xtimer_usleep_short/tests/01-run.py
@@ -6,7 +6,6 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 import pexpect